Same as Fig. 6 for streamlines anchored just beyond the sublimation radius: r₀ = R_sub  =  0.2 AU in the Class 0 and Class I, and 0.11 AU in the Class II. These calculations assume no self-shielding of H₂ or CO (i.e. no molecules surviving on streamlines launched inside R_sub). The resulting abundances set a minimum photodissociation timescale on outer streamlines, to be compared with the flow timescale (see Fig. 10).